Antiperspirant compositions are commonly applied to the skin at the underarms to prevent or alleviate perspiration. Such compositions take a variety of physical forms such as a stick, gel, cream, roll-on liquid, pump spray and aerosol spray. A popular form of an antiperspirant product is a gel. Gels can be made transparent (clear), translucent, or opaque. Clear gel antiperspirant compositions are preferred by consumers over opaque compositions for aesthetic reasons. Consumers associate clear transparent products with purity and freshness. Gels also provide a vehicle which glides easily over the surface of the skin resulting in easy and comfortable application of the antiperspirant product to the body. Additionally, clear gel antiperspirant compositions leave less residue or dust on the skin. For clear gel antiperspirants the gelling agents of choice have been the dibenzylidene alditols (e.g., dibenzylidene sorbitol) because they are able to form clear free standing gels. However, dibenzylidene alditols are unstable and degrade in certain formulation environs.
While dibenzylidene alditols are stable in alkaline and neutral media, these compounds are not stable when formulated in the presence of acidic antiperspirant active materials. In an acidic environment they deteriorate and liquefy resulting in a product which has a short self life. Moreover, the residue problem is not totally eliminated in that these compositions still leave a white, staining residue on contacted skin or clothing.
The present invention provides specific polymer gellants which, when utilized with acidic antiperspirant agents provide good opaque to transparent gel properties without the degradation problems that typically accompanies the use of dibenzylidene alditol gelling agents while avoiding a visible residue, e.g., a white layer, that is left on the skin or clothing after the antiperspirant composition is applied.